CLI state between calls (#175)

* add serialization

* add config

* change state

* final touches

Cargo.lock

@@ -2702,6 +2702,8 @@ dependencies = [
  "clap_derive",
  "color-eyre 0.6.2",
  "rln",
+ "serde",
+ "serde_json",
 ]
 
 [[package]]

rln-cli/Cargo.toml

@@ -8,3 +8,6 @@ rln = { path = "../rln" }
 clap = { version = "4.2.7", features = ["cargo", "derive", "env"]}
 clap_derive = { version = "=4.2.0" }
 color-eyre = "=0.6.2"
+# serialization
+serde_json = "1.0.48"
+serde = { version = "1.0.130", features = ["derive"] }

rln-cli/src/config.rs

@@ -0,0 +1,29 @@
+use color_eyre::Result;
+use serde::{Deserialize, Serialize};
+use std::{fs::File, io::Read, path::PathBuf};
+
+pub const RLN_STATE_PATH: &str = "RLN_STATE_PATH";
+
+#[derive(Default, Serialize, Deserialize)]
+pub(crate) struct Config {
+    pub inner: Option<InnerConfig>,
+}
+
+#[derive(Default, Serialize, Deserialize)]
+pub(crate) struct InnerConfig {
+    pub file: PathBuf,
+    pub tree_height: usize,
+}
+
+impl Config {
+    pub(crate) fn load_config() -> Result<Config> {
+        let path = PathBuf::from(std::env::var(RLN_STATE_PATH)?);
+
+        let mut file = File::open(path)?;
+
+        let mut contents = String::new();
+        file.read_to_string(&mut contents)?;
+        let state: Config = serde_json::from_str(&contents)?;
+        Ok(state)
+    }
+}

rln-cli/src/main.rs

@@ -7,6 +7,7 @@ use rln::public::RLN;
 use state::State;
 
 mod commands;
+mod config;
 mod state;
 
 #[derive(Parser)]
@@ -19,7 +20,7 @@ struct Cli {
 fn main() -> Result<()> {
     let cli = Cli::parse();
 
-    let mut state = State::default();
+    let mut state = State::load_state()?;
 
     match &cli.command {
         Some(Commands::New {

rln-cli/src/state.rs

@@ -1,6 +1,23 @@
+use color_eyre::Result;
 use rln::public::RLN;
+use std::fs::File;
+
+use crate::config::{InnerConfig, Config};
 
 #[derive(Default)]
 pub(crate) struct State<'a> {
     pub rln: Option<RLN<'a>>,
 }
+
+impl<'a> State<'a> {
+    pub(crate) fn load_state() -> Result<State<'a>> {
+        let config = Config::load_config()?;
+        let rln = if let Some(InnerConfig { file, tree_height }) = config.inner {
+            let resources = File::open(&file)?;
+            Some(RLN::new(tree_height, resources)?)
+        } else {
+            None
+        };
+        Ok(State { rln })
+    }
+}